Wireless communication technologies such as 802.11, Ultrawideband (UWB), and Bluetooth enable devices to communicate wirelessly over a relatively short range, e.g., less than 100 meters. Services may be provided by one device to another device using wireless communications once a connection is established between the two devices.
A variety of services may be provided over wireless communications between devices. As one example, a laptop computer may communicate wirelessly with a printer to print documents. Once a wireless connection is established between the computer and the printer, the computer may discover the print services provided by the printer. The computer may then take advantage of printing services offered by the printer via the wireless connection. Other examples of services that may be provided over wireless communications include headset connectivity and PDA connectivity.
Various wireless protocols, for example, Bluetooth, include a service discovery protocol. Wireless Service discovery protocols allow automatic detection of services offered by devices within the wireless proximity.
Many devices communicate using wireless protocols which are not specifically adapted for discovering proximity-based services. For example, many computers use 802.11 in an infrastructure mode to connect to a network through an access point. 802.11 can also be used in ad hoc mode to connect to local devices, but 802.11 does not include a service discovery protocol, which can make discovering a service cumbersome when using 802.11.
Many previously developed IP-based methods of discovering services require a connection to be established with a device before services provided by a device can be discovered. For example, network discovery protocols such as SSDP (Simple Service Discovery Protocol), WS-Discovery (Web Services Discovery), and SLP (Service Location Protocol) require network layer connectivity (Layer 3 of the OSI model) to be established prior to the discovery of services on the network. Once connected, services provided by a device send broadcast or multicast messages over the IP network to advertise their services.